The present invention generally relates to pallet jacks. In particular, the present invention relates to a device for decreasing a turning radius of a pallet jack.
In the art of material handling, pallets jacks (or pallet trucks) typically include wheeled devices intended for the manual lifting of a pallet, with a load resting thereon, to transport the pallet and load from one work area to another. U.S. Pat. No. 4,589,669 discloses an exemplary pallet jack, or hydraulic pallet truck. Pallet jacks typically include forked support arms upon which extensible rollers are mounted at terminal ends. The opposing ends of the forked support arms are typically connected to one another and attached in some fashion to a pivotal wheel with a hydraulic lift. The pivotal wheel allows the user to steer the pallet jack when either pushing or pulling the pallet jack. The hydraulic lift is operatively connected the wheel and the extensible rollers to raise and lower the support arms to engage and transport the pallet or to disengage the pallet jack from the pallet.
Due to the relatively heavy loads pallet jacks are intended to transport, and the size of the pallets themselves, the length of the forked arms are designed to provide the greatest support and stability when in contact with the pallets. Therefore, to maximize stability, the roller of each fork is terminally positioned on each fork to maximize the distance each roller is from the main wheel. However, by positioning the rollers at such a distance from the main wheel, the pallet jack is sometimes difficult to steer in tight or crowded work areas due to the fact that the turning radius of the pallet jack is defined by the distance between the main wheel and the rollers. The turning radius of the pallet jack becomes especially problematic when the work area does not provide for adequate space, as is the case with crowded warehouses or storerooms. Also, because the steerable wheel is positioned at one end and the rollers are positioned at the opposite end, the center of curvature of the pallet jack is virtually positioned between the rollers at the terminal ends of the forked arms. Therefore, positioning the forked arms to engage the pallet is made difficult because very little lateral movement occurs at the terminal ends of the forked arms relative to lateral movement made at the opposing end having the main steering wheel.
U.S. Pat. Nos. 7,226,060 and 7,427,075 teach the use of a device for decreasing the turn radius of an empty pallet jack. It has been discovered, though, that such devices have a tendency to impede the ability of inserting the support arms of a pallet jack within certain pallets for the lifting and moving thereof. As most pallets commonly include a lower cross-beam over which the support arms of the pallet jack must travel to position the pallet jack to lift the pallet, the rigid devices as taught in the aforementioned patents are sometimes difficult to pass over said cross-beams.